Rotary fluid power device

ABSTRACT

A power device capable of being used as either a fluid motor or a rotary pump, having a rotary abutment with two opposed valving recesses and four rotary pistons disposed in the same rotary plane and in operative circumferential engagement with the rotary abutment. The device comprises a pair of fluid power units connected in two parallel fluid circuits, each circuit having two pistons connected in series. The rotary pistons are balanced so that diametrically opposed pistons in different circuits are working, while the other pair of diametrically opposed pistons in the different circuits are valving. The appendages are designed with maximum working faces and with a minimum radial dimension, by relieving the base of the appendage to form flat diverging shoulders.

United States atent 1191 K li ki 5.] Apr. 10, 1973 [54] ROTARY FLUID POWER DEVICE [57] ABSTRACT [76] Inventor: Robert A. Kolinski, 815 Gilbreth A power device capable of being used as either a fluid Drive, Lawrenceburg, Tenn. 38464 motor or a rotary pump, having a rotary abutment Filed Oct 28 1971 with two opposed valving recesses and four rotary pistons disposed in the same rotary plane and in [21] Appl. No.: 193,509 operative circumferential engagement with the rotary abutment. The device comprises a pair of fluid power 52 US. Cl ..418/7 418/199 i cmmected Parallel i circuits each 511 Im. Cl..........:F(l1c 1/30 F03c 3/00 F04c 11/00 cPthavingtw" psmnsconnecteimSe? The Mary [58] Field of Search .:.....418/7 1 0 196 199 pfswns P P dlametrlcany 5 pistons in different circuits are working, while the other pair of diametrically opposed pistons in the dif- [56] References Cited ferent circuits are valving.

The a enda es are desi ed with maximum workin UNITED STATES PATENTS faces 25d witfi a minirnun r radial dimension, by reliev 83,483 10/1868 Goben ..4l8/l96 g the base Of the appendage to form flat diverging 2,614,503 10/1952 shoulders 3,416,458 12/1968 3,457,835 7/1969 6 Claims, 6 Drawing Figures 3,502,032 3/1970 Primary Examiner-Carlton R. Croyle Assistant ExaminerJohn J. Vrablik Attorney-Harrington A. Lackey INVENTOR I EOBERTF. K04 //vJ/ ATTORNEY PATENTEDAFRWIW 3,726,615

SHEET 2 BF 2 ATTORNEY ROTARY FLUID POWER DEVICE BACKGROUND OF THE INVENTION This invention relates to a rotary fluid power device, and more particularly to a rotary fluid power device of the abutment type.

Rotary fluid power devices of the abutment type of a variety designs are known in the art.

In the design of such rotary power devices, there is a tendency to attempt to increase the capacity of these devices by extending the radial dimension of the appendage to present a greater working surface to the thrust of the pressurized fluid. The extension of the appendage requires both a deeper and a wider abutment recess in the abutment valve for receiving the appendage during the valving cycle. Larger abutmentrecesses tend to increase fluid leakage, particularly when the width of the recess becomes greater than the span of the closure.

Since, in typical rotary power devices, only one rotary piston at a time transmits power, then increased pressure against each appendage creates additional torque upon the rotary piston shaft and additional side loading against the rotary abutment valve producing greater stresses, more wear and shorter life to the parts and bearings. To accommodate these Additional problems, the parts of the devices are made larger, stronger and heavier, increasing their cost, energy consumption and inefflciency.

Furthermore, the extension of the radial dimension of the piston appendages also creates limitations upon the pressure of the fluid used in the hydraulic power devices when functioning as fluid motors.

Some attempts have been made to employ shorter appendages, or appendages of lesser radial extent, in order to obtain longer bearing life by using timing gears to double the rpm of the pistons relative to the output drive shaft for a fluid motor. However, the higher velocity of the rotary pistons results in increased energy losses.

The patent of Frank Berry U.S. Pat. No. 2,694,978 discloses a rotary power device of the abutment type employing a first set of a pair of balanced rotary pistons simultaneously working and valving on oppOsIte sides of the abutment valve. The Berry patent also includes a second set of balanced rotary pistons spaced axially of the first set of pistons in which the second set of pistons also work and valve simultaneously, but 180 out of phase with the pistons in the first set. One piston in each set is mounted upon the same rotary piSton shaft, while the other piston in each set is mounted upon a second rotary piston shaft. By axially spacing the two sets of rotary pistons, extreme loads alternately bear upon the rotary abutment shaft as well as the rotary piston shafts at axially spaced points, thus creating extreme demands on the bearings for all the shafts.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a rotary fluid power device of the abutment type which overcomes the above enumerated disadvantages.

The power device made in accordance with this invention includes a rotary abutment valve having a pair of opposed valving recesses, two sets of rotary pistons connected in parallel fluid circuits on opposite sides of and in the same rotary plane as, the rotary abutment valve, each set having a pair of rotary pistons in series. The pistons are spaced equidistantly, that is apart, around the circumference of the abutment valve, and the pistons are consecutively 90 out of phase, so that the opposed pistons in opposite parallel circuits are working simultaneously, while the other pair of pistons in the opposite parallel circuits are simultaneously valving. Moreover, all of the pistons are located in the same rotary plane as the rotary abutment valve so that the loads exerted by the opposed pistons during their working cycles are equal and opposite in the same plane, regardless of which pair of opposed pistons are working.

Each piston rotates in the same direction at the same velocity, but at twice the velocity of the rotary abutment valve. Accordingly, the output of the device functioning as a fluid motor is twice the capacity of either set of pistons.

The appendages are relatively short with a maximum working surface, by virtue of the bases of the valves being relieved and forming flat shoulders diverging at angles from the opposed flat surfaces of each appendage. Although the abutment valve recesses are substantially larger than the corresponding appendages, nevertheless they are still small enough to be completely sealed by the opposed closure surfaces which are designed to completely span each recess as they rotate past the closure surfaces.

A rotary fluid power device made in accordance with this invention and functioning as a motor, may incorporate two motor units with parallel fluid circuits. For example, the rating of each motor unit may be 15 H.P. and 14 gallons per minute with a flow velocity of 12 ft. per second at 2000 R.P.M., 2000 psi fluid pressure and a torque of 475 lb-inches. The output of such a dual fluid motor device would be 30 H.P., 28 gallons per minute, with the same flow velocity of 12 ft. per second at 2000 R.P.M. and 2000 psi fluid pressure for a resulting torque of 950 lb.-inches. Moreover, all of this pressure is balanced internally and externally.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of a rotary power device incorporating this invention;

FIG. 2 is a reduced section taken along the lines 2-2 of FIG. 1, disclosing one opposed pair of rotary pistons in their working cycle, while the other two pair of rotary pistons are in their valving cycles;

FIG. 3 is a view similar to FIG. 2 disclosing a subsequent cycle of operation in which the rotary pistons have rotated through 90;

FIG. 4 is a view similar to FIG. 2 inwhich the rotary pistons have rotated through FIG. 5 is a view taken along the line 5-5 of FIG. 1; and

FIG. 6 is an enlarged fragmentary view similar to FIG. 2, to better illustrate the piston and rotor chamber construction.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in more detail, FIG. 1 discloses a rotary fluid power device 10 made in accordance with this invention including a housing 11, preferably separated into sections and secured together by bolts 12 (FIGS. 2-6) to facilitate maintenance and replacement of parts.

Journaled for rotational movement longitudinally and centrally of the housing 11, by bearings, such as roller bearings 13 is abutment shaft 15.

Fixed to the left or front end of the abutment shaft 15 is a sun gear 16. Meshing with the periphery of the sun gear 16 are four planetary gears, only two of which, 17 and 18, are disclosed in FIG. 1. All four planetary gears, including 17 and 18, mesh with the internal ring gear 19 fixed to power shaft 20, which is joumaled in ball bearings 21 to project through the front end of the housing 1 l.

The planetary gears 17 and 18 are fixed to the front ends of piston shafts 23 and 24. In a similar manner, the undisclosed planetary gears are fixed on the front ends of the piston shafts 25 and 26. Since all of the planetary gears 17 and 18 are of equal size, all of the piston shafts 23, 24, 25 and 26 will rotate in the same direction at the same velocity.

The sun gear 16 is twice the diameter of any of the planetary gears 17 and 18 causing the abutment shaft 15 to rotate in the opposite direction at half the speed of any of the piston shafts 23-26.

Mounted upon the abutment shaft 15 within the power section 28 is a cylindrical, rotary abutment valve 30. Formed longitudinally or axially in diametrically opposite surfaces of the cylindrical abutment valve 30 are a pair of valving recesses 31 and 32, each of which is substantially U-shaped and of uniform width.

The rotary abutment valve 30 is adapted to rotate in peripheral engagement'with arcuate end closures 33 and 34 of closure walls 35 and 36 forming an integral part of the housing 11. The closure walls 35 and 36 and the rotary abutment valve 30 form a substantially solid partition between parallel fluid power units 39 and 40.

Power unit 39 includes an inlet channel 41 communicating in a series fluid circuit with rotor chamber 4'2, connecting passageway 43, rotor chamber 44 and fluid outlet channel 45.

Extending through the rotor chamber 42 is the piston shaft 23 supporting the rotary piston 46. In a similar manner, extending through the rotor chamber 44 is the piston shaft 24 to which is fixed the rotary piston 47 The second fluid power unit also includes a fluid circuit in which fluid flows in the opposite direction from the fluid circuit of unit 39, and includes, in series, a fluid inlet channel 51, rotor chamber 52, fluid passageway 53, rotor chamber 54 and fluid outlet channel 55.

Extending coaxially through the rotor chamber 54 is the piston shaft 25, while extending coaxially through the rotor chamber 52 is the piston shaft 26. Fixed to the piston shaft 25 is the rotary piston 56, while fixed to the piston shaft 26 is the rotary piston 57.

As best disclosed in FIG. 5, both inlet channels 41 and 51 may be supplied through branch conduits 58 and 59 from main inlet supply conduit 60 from any source of pressurized fluid, not disclosed. In a similar manner, both fluid outlet channels 45 and'55 may exhaust the fluid through branchoutlet conduits 61 and 62 to the main discharge conduit 63.

As best disclosed in FIG. 6, the rotary piston 46 comprises a cylindrical segment 65 extending through an arc of at least 192, and preferably approximately 200. Extending from the rotary piston 46' on the opposite side from the cylindrical segment 65 is the radial appendage or vane 66, preferably of uniform thickness and having opposed flat work surfaces 67 and 68 and a tip 69. The flat surfaces 67 and 68 are not only parallel to each other, but are parallel to the radial axis of the appendage 66.

As best disclosed by the extension line 70 of the cylindrical surface of the segment 65, the base of the appendage 66 has been relieved in order to provide a greater working surface, without extending the tip 69 of the appendage 66. Furthermore, the base of the appendage 66 has been relieved in such a manner as to form shoulders 71 and 72, preferably flat and diverging from the respective appendage surfaces 67 and 68 at dihedral angles A. The opposite ends or edges of the shoulders 71 and 72 terminate by intercepting the ends of the cylindrical surface of the segment 65.

As best disclosed in FIG. 6, in the rotor chamber 44, when the pressurized fluid is driving the appendage 66' in the direction of the arrow, the appendage working surface 67' will be greater because the appendage 66' extends farther into the base of the piston 47. In other words, the vector pressure components at right angles to the radius of the rotary piston 47, applied to the shoulder 71, are effective in producing corresponding moments about the center of the piston 47.

Also as illustrated in FIG. 6 in rotor chamber 42, by relieving the mass of the piston 46 between the cylindricalprojected surface 70 and the shoulder 71, a

' between the recess 31 and the appendage 66.

In a preferred form of the invention, the dihedral angle A between the appendage surface 67 and the shoulder 71, and also the surface 68 and shoulder 72, is approximately l30.

As illustrated in FIG. 2, the appendages 66', 66 166 and 166' are consecutively out of phase by By virtue of this angular arrangement, the appendages 66 and 166 of the opposed pistons 46 and 57 always extend radially in opposite directions. Accordingly, in FIG. 2, the appendages 66 and 166' are extending directly toward each other on diametrically opposite sides of the rotary abutment 30 and are also simultaneously valving through the opposed recesses 31 and 32, which are timed to cooperate with the appendages 66 and 166' through their valving cycles.

In a similar manner, the appendages 66' and 166 of the opposed pistons 44 and 56 also extend radially in opposite directions at all times, and in the particular position of FIG. 2 are in the middle of their working cycles directed away from each other, with the segments 65 in rolling bearing engagement against the cylindrical surface of the rotary abutment valve 30. Thus, in FIG. 2, in the power unit 39, the rotary piston 46 is valving 'while the other piston 47 is working. In a similar manner in the power unit 40, the piston 57 is valving, while the other piston is working.

In FIG. 3, the abutment valve 30 is rotated through 45, while each of the pistons 46, 47, 56, and 57 have rotated twice as fast through 90, so that pistons 46 and 57 are just beginning their working cycles, while pistons 47 and 56 are just ending their working cycles. Moreover, since none of the appendages of any of the pistons are cooperating at this instant with the recesses 31 and 32, the recesses 31 and 32 are passing their respective arcuate end closures 33 and 34 to trap any fluid within the recesses 31 and 32, respectively, to prevent leakage from one power unit 39 to the other power unit 40.

In FIG. 4, the abutment valve 30 has rotated through an additional 45, while the rotary pistons 46, 47, 56 and 57 have rotated twice as fast through an additional 90, so that the pistons in each power unit 39 and 40 have reversed their relative positions in the valving and working cycles revealed in FIG. 2.

Accordingly, in every angular position of the rotary pistons 46, 47, 56 and 57, the loads and pressures are balanced on opposite sides of the rotary abutment valve 30. Moreover, each power unit 39 and 40 is continuously producing power simultaneously. If the fluid is supplied under pressure through the inlet channels 41 and 51, the device functions as a fluid motor, which in effect is a pair of fluid motors 39 and 40 functioning in two parallel fluid circuits on opposite sides of a single rotary abutment valve 30.

In order to minimize vibration, the exit from the rotor chamber 42 is enlarged by providing a diverging wall portion 74 intercepting the passageway 43 (FIG. 6). In a similar manner, the entrance area from the passageway 43 into the rotor chamber 44 is enlarged to converge into the rotor chamber 44 by means of the converging wall portion 75. The pressure of fluid entering the rotor chamber 42 from the inlet channel 41 is gradually increased by virtue of the appendage 66 moving across the exit from the channel 41 and into cooperation with the wall of the rotor chamber 42. In a similar manner, the entrance area from the passageway 43 into the rotor chamber 44 is enlarged to converge into the rotor chamber 44 by means of the converging wall portion 75. The pressure of fluid entering the rotor chamber 42 from the inlet channel 41 is gradually increased by virtue of the appendage 66 moving across the exit from the channel 41 and into cooperation with the wall of the rotor chamber 42. In a similar manner, the pressure of the fluid exhausting from the rotor chamber 44 is gradually decreased by virtue of the appendage 66' moving away from the intersection of the wall of the chamber 44 and the outlet fluid channel 45.

Accordingly, the movement of fluid and the change in fluid pressure is gradually increased at the beginning of the work cycle of each rotary'piston, while it is gradually relieved at the end of each working cycle.

In a preferred form of the invention, the arc of the cylindrical segment 65 is approximately 200. The working arc of the cylindrical surface of each rotor chamber is preferably about 192, which is 12 greater than a half-cylinder. Accordingly, there is a 6 overlap between the working cycle of the pair of rotary pistons within each power unit 39 or 40. This'overlapping of working cycles is an insurance against interruption of i the transmittal of power through the piston shaft to the power shaft 20.

It will be obvious that by mechanically driving the power shaft 20, fluid may be forced through the parallel circuits in the power units 39 and 40 to provide, in effect, a pair of equal-capacity pumps, about a single rotary abutment valve 30.

By supplying fluid through the main conduit 63 and discharging it through the main conduit 60, the direction of rotation of the power shaft of the device 10, functioning as a motor, will be reversed.

It will also be understood, that even though all of the details of the rotary pistons 46 and 47, appendages 66 and 66, shoulders 71 and 71, and the diverging and converging wall portions 74 and 75, were described in connection with the power unit 39, that the corresponding parts of the power unit 40 are constructed identically.

What is claimed is:

1. A rotary fluid power device comprising:

a. an elongated housing,

b. a cylindrical rotary abutment mounted in said housing for rotary movement about a longitudinal axis,

c. a pair of opposed valving recesses in the surface of said rotary abutment,

. at least four, substantially cylindrical, rotor chambers disposed parallel to, in the same rotary plane of, and equally spaced apart circumferentially of, said rotary abutment,

e. a rotary piston mounted coaxially within each corresponding rotor chamber and in the same rotary plane as said rotary abutment, for rotary movement,

f. each of said pistons having a cylindrical segment adapted to rollably engage said rotary abutment during the working cycle of said piston, and an appendage projecting radially from the opposite side of said piston from said segment and adapted to'be received in either of said abutment recesses during the valving cycle of said piston,

. a first closure wall in said housing separating a pair of rotor chambers, and a second closure wall in said housing separating another pair of rotor chambers,

. said closure walls terminating in opposed arcuate end closures engaging said rotary abutment and adapted to span and close said abutment recesses as said recesses rotate past said end closures,

i. each of said appendages being consecutively and uniformly out of phase, so that the appendages on a pair of diametrically opposed pistons project in opposite directions, and the appendages on another pair of diametrically opposed pistons project in opposite directions,

j. a first passage for fluid through the rotor chambers in series on one side of said closure walls, and a second passage for fluid through the rotor chambers in series on the opposite side of said closure walls,

k. gear means drivingly coupling said rotary pistons to said rotary abutment, and

l. a power shaft drivingly coupled to said gear means.

2. The invention according to claim 1 in which the width of said abutment recess is substantially greater than the thickness of each appendage to permit free flow of fluid through each recess when an appendage is received in said recess, said recess width being less than the arcuate width of each end closure.

3. The invention according to claim 2 in which the width of each abutment recess is at least twice as great as the thickness of each appendage.

4. The invention according to claim 1 in which the arc of the cylindrical surface of each segment is at least 192, each appendage comprises opposed flat surfaces substantially parallel to the radius of its corresponding of said first and second passages comprises a passageway between said corresponding rotor chambers in series formed between a portion of said housing and said rotary abutment, a portion of each rotor chamber wall intercepting said passageways diverging radially away from the rotary piston in said corresponding chamber toward said respective passageway. 

1. A rotary fluid power device comprising: a. an elongated housing, b. a cylindrical rotary abutment mounted in said housing for rotary movement about a longitudinal axis, c. a pair of opposed valving recesses in the surface of said rotary abutment, d. at least four, substantially cylindrical, rotor chambers disposed parallel to, in the same rotary plane of, and equally spaced apart circumferentially of, said rotary abutment, e. a rotary piston mounted coaxially within each corresponding rotor chamber and in the same rotary plane as said rotary abutment, for rotary movement, f. each of said pistons having a cylindrical segment adapted to rollably engage said rotary abutment during the working cycle of said piston, and an appendage projecting radially from the opposite side of said piston from said segment and adapted to be received in either of said abutment recesses during the valving cycle of said piston, g. a first closure wall in said housing separating a pair of rotor chambers, and a second closure wall in said housing separating another pair of rotor chambers, h. said closure walls terminating in opposed arcuate end closures engaging said rotary abutment and adapted to span and close said abutment recesses as said recesses rotate past said end closures, i. each of said appendages being consecutively and uniformly out of phase, so that the appendages on a pair of diametrically opposed pistons project in opposite diRections, and the appendages on another pair of diametrically opposed pistons project in opposite directions, j. a first passage for fluid through the rotor chambers in series on one side of said closure walls, and a second passage for fluid through the rotor chambers in series on the opposite side of said closure walls, k. gear means drivingly coupling said rotary pistons to said rotary abutment, and l. a power shaft drivingly coupled to said gear means.
 2. The invention according to claim 1 in which the width of said abutment recess is substantially greater than the thickness of each appendage to permit free flow of fluid through each recess when an appendage is received in said recess, said recess width being less than the arcuate width of each end closure.
 3. The invention according to claim 2 in which the width of each abutment recess is at least twice as great as the thickness of each appendage.
 4. The invention according to claim 1 in which the arc of the cylindrical surface of each segment is at least 192*, each appendage comprises opposed flat surfaces substantially parallel to the radius of its corresponding rotary piston, the surface of said piston being relieved at the base of said appendage to provide flat shoulders intercepting said appendage surfaces in dihedral angles within the projected cylindrical surface of said rotary piston, the other ends of said shoulders terminating at the ends of the cylindrical surface of said segment.
 5. The invention according to claim 4 in which said dihedral angle is approximately 130*.
 6. The invention according to claim 1 in which each of said first and second passages comprises a passageway between said corresponding rotor chambers in series formed between a portion of said housing and said rotary abutment, a portion of each rotor chamber wall intercepting said passageways diverging radially away from the rotary piston in said corresponding chamber toward said respective passageway. 